Automatic power control module for battery powered devices

ABSTRACT

A power control module which can be used to automatically open a power circuit for electrically operated devices, particularly battery operated devices, during predetermined periods of non-use. A timer is reset by a motion detector indicating continuing use. The timer controls a transistor switch which closes and opens the power circuit as required. The timing interval can be user-selected e.g., by programming a microprocessor controller. The transition time between conductive and non-conductive states of the transistor can also be controlled to prolong the life of incandescent bulbs or other sensitive load devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 10/763,504, filed Jan. 22, 2004, entitled AUTOMATIC POWER CONTROLFOR BATTERY POWERED DEVICES to which a claim of priority is hereby madeand the disclosure of which is incorporated by reference herein.

This application is also related to my U.S. Pat. No. 6,642,667, theentire disclosure of which is also incorporated by reference herein, andwhich includes reference to other patents that reflect the current stateof the art.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to a control module for battery operateddevices, which functions to open the battery circuit after apredetermined period of non-use. A timer including a motion detector isprovided to re-close the battery circuit and reset the timer. The deviceis self-contained and is configurable so that it can easily beaccommodated in many existing products without the need for redesign, orwith only minimal redesign. The invention can have utility inflashlights, toys, and numerous other battery-operated devices for whichpower is needed only when the device is actually in use.

2. Relevant Art

A known problem with battery-powered devices, such as flashlights, toys,etc. is that they are often inadvertently left on after use, resultingin the cost and inconvenience of premature replacement of batteries. Toavoid this, some battery-powered devices, include timers as part of thecircuitry which shut the devices down, or initiate a standby mode aftera predetermined period of non-use. Several such devices are mentioned inmy above-referenced patent. There do not, however, appear to becommercially available shut-off devices adaptable to a wide range ofproducts which can simply be purchased off the shelf, and interfacedwith an existing product or design. Availability of such devices couldreduce design time and cost, and through standardization, reducecomponent and even assembly cost. A properly designed device of thiskind could be incorporated in many existing devices even by the enduser, or during manufacture with no redesign in many instances, or withonly minimum packaging and/or component layout redesign. A need for sucha device clearly exists.

Another known problem, particularly in devices such as flashlights, isthe need for frequent replacement of bulbs. Incandescent lamps forflashlights are rarely designed for long-life, and indeed, the oppositeis usually true. Light output is generally increased at the expense ofbulb life. Seemingly, spare bulbs are never at hand when needed, andreplacement is often inconvenient in any event. A practical way toincrease bulb life without reducing light output which could readily beincorporated in a flashlight would be desirable, but that, too, does notappear to be commercially available.

SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to satisfy theabove-described needs for a self-contained unit which provides aninactivity shut-off function and optionally, bulb-life enhancement, andwhich can be inserted in existing products with little or no redesign.

An additional object of the invention is to provide a control modulewhich can be used with a variety of existing electrical and electronicdevices to enhance utility through availability of programmablefunctions.

A further object of the invention is to provide a self-contained powercontrol module for battery operated devices which can be programmed foruse in a variety of applications with different operating parameters.

A power control module device according to one feature of the inventioncomprises an electronic circuit board including a timer, a timer resetcircuit, a transistor switch and an associated control circuit, and amotion detector, like an accelerometer. These are all mounted on acircuit board which can fit into many existing devices. The transistoris operable to open the battery circuit, thereby turning off a connectedload after a predetermined period of non-use such as two minutes, if thedevice remains motionless.

The battery circuit is reactivated if motion of the device triggers themotion detector to reset the timer which then remains on for another twominute interval. The timer can also be reset by turning a main switchoff and back on again. If the device is in constant motion, the motiondetector is repeatedly reset for successive two minute intervals and thedevice remains in operation.

According to a second feature of the invention, the module is in theform of a thin disc or plate. Different sizes can be provided for usewith different type batteries and battery compartment configurations.The module can then be installed in the battery compartment, in linewith, or adjacent to the batteries, with the transistor switch in serieswith the battery circuit.

According to a further feature of the invention, the switch controlcircuit can include a delay timer which provides for controlled turn onand turn off of the transistor switch to enhance the life of a loaddevice such as an incandescent lamp in a flashlight.

According to yet a further feature of the invention, an integratedcircuit programmable controller can be included to provide selectableinactivity time out intervals, and selective operation of the turnon-turn off delay, and other user-programmable functions.

According to another feature of the invention, the module can be usedwith remotely located motion sensors and also to control mains-poweredloads to provide programmable capabilities in devices lacking suchfeatures when purchased.

Other features and advantages of the present invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of a control module according to one embodimentof the invention designed for use with a standard nine volt batteryshowing a preferred mechanical arrangement of contacts and circuitelements.

FIG. 1B is a partially cross sectioned schematic view taken along line1-1 in FIG. 1A.

FIG. 2A is a plan view of a control module according to a secondembodiment of the invention designed for insertion between batteries ina battery box in series with the battery electrical circuit showing apreferred mechanical arrangement of contacts and circuit elements.

FIG. 2B is a partially cross sectioned schematic view taken along line2-2 in FIG. 2A.

FIG. 3 is a schematic side elevation drawing of the control module ofFIG. 2 inserted between batteries in a battery compartment.

FIG. 4A is a bottom plan view of a control module according to a thirdembodiment of the invention similar to that shown in FIG. 2 but with aterminal clip to provide for attachment to a battery and provide bothpolarities (+) and (−) of the battery voltage to be available to operatethe time-out circuit with a minimum of voltage drop to the system'sseries battery circuit.

FIG. 4B is a partially cross sectioned schematic view taken along line4-4 in FIG. 4A.

FIG. 5A is a schematic type drawing of the control module of FIG. 4 withthe battery attachment and voltage supply clip insert into a typicalbattery compartment.

FIG. 5B is an enlarged view of a portion of FIG. 5A.

FIG. 6 is a block diagram of the circuitry of an automatic time-outshut-off device with movement sensing reset according to the invention.

FIG. 7 is a flow chart showing the operational characteristics of theautomatic time-out shut-off device with movement sensing reset.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1A and 1B show schematically a first embodiment of an automaticshut-off control module, generally denoted at 1. This is configured foruse with a standard nine volt battery. Shut-off device 1 includes a baseplate 9 which is preferably a printed circuit board (PCB) fabricated inconventional fashion. On one side 9A of PCB 9 are mounted a transistorswitch 4, a control unit 5 including a timer, a timer reset circuit, anda driver for transistor 4, a motion sensor 6, a female snap connector 2and a male snap connector 3. Connectors 2 and 3 are configured forrespective attachment to the male (positive) and female (negative)terminals of a nine volt battery (not shown).

Mounted on the other side 9B of PCB 9 are snap terminals 2A and 3A,respectively aligned with terminals 2 and 3. Terminal 2A is male tocorrespond to the male positive terminal of the battery, and terminal 3Ais female to correspond to the female negative terminal of the battery.Terminals 3 and 3A are electrically connected by a conductive sleeve 3Bto provide a direct connection through the circuit board to the negativeterminal of the battery. Terminals 2A and 3A are intended for connectionin conventional fashion to provide operating power for a load devicethrough a main on-off switch (both of which are not shown in theinterest of simplicity).

As described in more detail below in connection with FIG. 6, transistor4 provides a switched connection between positive terminals 2 and 2A,which are accordingly connected to the emitter and collector terminalsif a junction transistor is employed, or to the source and drainterminals when a MOSFET or the like is employed.

Thus, when the main switch is turned on, transistor 4 is switched to itsconductive state, and the battery circuit through contacts 2 and 2A isclosed, permitting the load device to operate. As long as the timer incontrol circuit 5 is repeatedly reset by motion sensor 6 within itstiming interval, transistor 4 remains conductive, and the batterycircuit remains energized. However, if the timer times out, transistor 4is switched to its non-conductive state and the battery circuit isopened. Transistor 4 remains non-conducting, and the battery circuitremains open, until motion is again detected, or the main switch for theload device is turned off, then on again.

Alternatively, positive terminals 2 and 2A can be connected-through onthe circuit board with the transistor providing a switchable pathbetween negative terminals 3 and 3A, depending on the type of transistorused and the design of the electronic circuit.

An outer skirt 7 formed of any suitable resilient material, may beinsert molded onto circuit board 9 to give it orientation for connectionto the battery terminals and help hold it in place along with its snapconnectors 2 and 3.

Control circuit 5 can be fabricated as an integrated circuit on a customcircuit silicon die (a small chip of silicon with custom circuitry suchas a computer chip) for high volume, low cost production. The chip ispreferably surface mounted as shown on PCB 9 and then encapsulated withepoxy or the like onto board 9 for moisture and mechanical protection.Depending on the heat dissipation requirements, transistor 4 may be partof chip 5, or may be separately mounted and encapsulated, as shown.

Motion detector 6 for the control module 1 in FIG. 1 is comprised of asmall metal ball 6A movably enclosed under an arcuate metal conductivecover 6C and is positioned and configured to make interrupted contactwith an arcuate circuit trace 6B on PCB 9 as movement of device 1 causesmotion of the ball. This intermittent contact closure continuouslyresets the timer in control circuit 5 as described below in connectionwith FIG. 6.

FIGS. 2A and 2B illustrate a second embodiment of the automatic time-outshut-off device, generally denoted at 10. This is configured to beplaced between two series-connected batteries 31 and 32 mounted in abattery compartment 30 such as the barrel of a flashlight or the like,as shown in FIG. 3. For simplicity, the load device and the main on-offswitch are not illustrated.

Control module 10 includes a switching transistor 14, a control circuit15, and a motion sensor 16, all of which may be respectively the same asor similar to transistor 4, control circuit 5, and motion sensor 6previously described in connection with the embodiment of FIGS. 1A and1B. All of these components are mounted on a PCB 19 with the transistorand control circuit encapsulated, also as described above.

As will be appreciated, PCB 19 is sized and configured to fit intobattery compartment 30 with the overall thickness of device 10 beingaccommodated by compression of spring 34 at one end of batterycompartment 30.

The outside edge of PCB 19 can be encapsulated with a resilient strip 17made of rubber or the like, with a flexible tab 18 for aiding inremoving the batteries from the battery compartment 30 as shown in FIG.3.

When device 10 is installed, terminals 12 and 12A are respectively incontact with terminals 35 and 36 of batteries 31 and 32. Terminals 12and 12A are insulated from each other by circuit board 19, and thusprovide a break in the battery circuit for the load. Closure of thebattery circuit is effected by connection of terminals 12 and 12A inseries with the current path of transistor 14, e.g., with the collectorand emitter terminals in the case of a junction transistor, or with thesource and drain terminals of a MOSFET or the like, as in the embodimentof FIGS. 1A and 1B.

Also as in the embodiment of FIGS. 1A and 1B, when the main switch forthe load device is turned on, transistor 14 is switched to itsconductive state, and the battery circuit is completed. As long as thetimer in control circuit 15 is repeatedly reset by motion sensor 16within its timing interval, transistor 14 remains conductive, and thebattery circuit remains energized. However, if the timer times out,transistor 14 is switched to its non-conductive state and the batterycircuit is opened. Transistor 14 remains non-conducting, and the batterycircuit remains open, until motion is again detected, or the main switchfor the load device is turned off, then on again.

FIGS. 4A and 4B illustrate a power control module, generally denoted at40, which is similar to device 10 of FIGS. 2A and 2B, but also includesa spring clip connector 50 preferably formed of an electricallyconductive material, and having first and second circular end plates 51and 52, and a connecting arm 41. Control module 40 is attached to endplate 52 in any suitable manner, as discussed more fully below. Springclip connector 50 is configured to snap onto a cylindrical battery 54installed with one or more additional batteries 54A in a batterycompartment 55, as illustrated in FIG. 5. When spring clip 50 isattached to battery 54, a contact area 41A on end plate 51 is connectedto the negative battery pole 56, and a contact 42 on module 40 isconnected to positive battery pole 60.

Control module 40 includes a switching transistor 44, a control chip 45including a timer and timer reset circuit, and a motion detector 46, allmounted as previously described on a PCB 49. A second terminal 42A onthe side of PCB 49 opposite to terminal 42 permits connection of thebatteries and the control module in the battery circuit for the loaddevice (not shown). For this purpose, end plate 52 includes a circularcentral aperture 61 through which terminal 42A is accessible. As will beappreciated, module 40 is secured to the margin of aperture 62. This maybe done by a suitable adhesive, or in the process of encapsulatingtransistor 44 and control chip 45.

Transistor 44 and control chip 45 function in the same way as transistor24 and control chip 25 in the embodiment of FIGS. 2A and 2B to connectterminals 42 and 42A when the battery circuit is intended to beenergized, and to break the connection between terminals 42 and 42A whenthe battery circuit is intended to be de-energized.

With the construction of FIGS. 4A and 4B, electrical connections to bothpoles 58 and 60 of battery 54 are available at module 40. This permitsoperation of the control device with a minimum series circuit voltagedrop.

FIG. 6 shows a basic block diagram schematic of the electrical controlcircuitry of the automatic time-out device with its flow-chartedoperational characteristics shown in FIG. 7.

In FIG. 6, a generalized module 70 is shown connected between batteryinput terminals 62 and 62A in a series circuit comprised of a battery72, a load 74 and a main on-off switch 76. Connection between terminals62 and 62A is through the current path of a transistor switch 65.

Control module 70 is also comprised of a control circuit 65A whichdrives transistor 65 into and out of conduction as required, a timercircuit 64 and a timer reset circuit 64A, and a motion detector 66.Control circuit 65A and timer 64 respond to an off-on transition ofswitch 76 to start the timing interval and to place transistor 65 in thefully conductive state. This completes the battery circuit throughterminals 62 and 62A, and energizes load 74. Timer reset circuit 64A,and motion detector 66 cooperate to reset timer 64 whenever motion isdetected.

If the timing interval ends without motion being detected, timer circuitoperates control circuit 65A to place transistor 65 in itsnon-conductive state. This opens the battery circuit and energizes load74. A long as switch 76 remains closed, motion sensed by detector 66will reset timer 64 and transistor 65 will again be placed in itsconductive state to re-energize the battery circuit. A similar result isobtained if main switch 76 is opened and re-closed.

No exact electrical circuit implementation for module 70 is disclosed,as many circuits capable of performing the functions described will bereadily apparent to those skilled in the art.

In this connection, it should be recognized that the required functionsmay readily be provided by a programmed microprocessor implementation.That has the advantage of facilitating programmed setting of a desiredtime out interval, and also selectable provision of controlled turn onand turn off of transistor 65.

It should also be recognized that the life of certain devices such anincandescent bulbs or sensitive electronic devices can be significantlyincreased if they are not subjected to the shock of large currentchanges when they are energized and de-energized. This can be achievedaccording to the present invention by incorporating into transistorcontrol circuit 65A a delay feature providing a staged transition, e.g.,over a one or two second interval, between the conductive andnon-conductive states of transistor 65. Various ways of doing this, bothin a circuit implementation of control circuit 65, or as part of amicroprocessor implementation, will be readily apparent to those skilledin the art.

The resulting soft turn on and turn off current to the incandescentfilament, etc., can greatly enhance the life of such a device.Additionally, either or both the automatic turn off and the controlledtransition functions can be made selectable, especially bypreprogramming in a microprocessor implementation, while use of switchesor the like to provide this function (or time-out interval selection)might prohibitively increase the size of the module.

The programmable microprocessor implementation with a suitable interfacesuch as a PC or dedicated input device can also allow use of the controlmodule for programming customized on/off control of a variety ofexisting battery operated devices, or even mains-operated devices. Forthe latter purpose, module could be incorporated in a unit having a plugfor direct connection to the wiring, and a receptacle for providingpower to the controlled device. Thus, on/off control desired forparticular time of day, for example, for home lighting, heating or anoven could be provided. Additionally with suitable motion detectors(including, if desired, remote detectors), the device can readily beused as an intrusion detector for homes to provide an alarm and turn onlights as desired. Other applications will also be readily apparent tothose skilled in the art.

The motion detector can be a number of different types known in the artsuch as accelerometers, mechanical vibration sensors vibrating wires,etc., as well as various non-contact sensors for detecting motion involumes of space such as rooms. For example, a drop of mercury couldreplace the ball to make and break contact with the traces on thecircuit board.

Therefore, while the present invention has been described a relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It istherefore intended that the present invention not be limited by thespecific disclosures herein but that it be afforded the full scopedefined by the appended claims.

1. A self-contained power control module for a battery operated device comprising: a support base for the module constructed and configured to be removably installed in a battery compartment, and conformable to standard battery configurations; first and second normally open electrical terminals positioned and configured to couple the module between a battery and a load device when the module is installed in the battery compartment; an electronic switch coupled between the first and second terminals, the switch being operable between conductive and non-conductive states by control signals applied thereto to close and open a circuit between the first and second terminals; a control unit for providing control signals to the electronic switch; a timer including reset capability; and a motion detector responsive to motion of the module to provide a reset signal for the timer, and wherein: the timer is operative when reset to initiate a predetermined timing interval; and the control unit is operative during the timing interval to maintain the electronic switch in the conductive state, and to maintain the electronic switch in the non-conductive state otherwise.
 2. A power control module as in claim 1, wherein the timer and the control unit are included in a programmable microprocessor controller.
 3. A power control module as in claim 2, wherein the microprocessor is operable to permit selection of the timing interval.
 4. A power control module as in claim 2, the microprocessor is operative to provide a gradual transition between the conductive and non-conductive states of the electronic switch, whereby the current in the battery circuit changes gradually when the battery circuit is energized and de-energized.
 5. A power control module as in claim 4, wherein the microprocessor is operative to permit selectable activation and deactivation of the gradual transition between the conductive and non-conductive states of the electronic switch.
 6. A power control module as in claim 4, wherein the microprocessor is operable to permit selectable activation and de-activation of the timed on-off function and/or the gradual transition between the conductive and non-conductive states of the electronic switch.
 7. A power control module as in claim 1, wherein the control unit is operative to provide a gradual transition between the conductive and non-conductive states of the electronic switch, whereby the current in the battery circuit changes gradually when the battery circuit is energized and de-energized.
 8. A power control module as in claim 1, wherein the motion sensor is positionable remotely from the power control module and is electrically connectable thereto.
 9. A power control module as in claim 1, wherein the module support base and first and second contacts are configured so the module is positionable between two batteries in series in a battery compartment, and wherein the first contact is connected to the positive term of a first battery and the second contact is connected to the negative terminal of the second battery.
 10. A power control module as in claim 1, further inclining an elongated resilient member having an electrically conductive path from a first end thereof to a second end, and wherein: the resilient member is electrically connected at the first end to the control module, and has a contact member at the second end connected to the conductive path, the resilient member is configured to clip onto opposite ends of a cylindrical battery with one terminal of the module connected to a first end of the batt and the contact member on the resilient member connected to an opposite end of the battery, whereby electrical connections to both ends of the battery are available for operating the control module.
 11. A power control module as in claim 1, further including third and fourth terminals mounted on the support base for the module, and wherein: the first and second contacts are positioned on the support base in axial alignment with each other, on opposite sides of the support base the third and fourth terminals are positioned on the support base in axial alignment with each other, on opposite sides of the support base; the third and fourth terminals are electrically connected together through the support base; the alignment axis of the first and second terminals is spaced from the alignment axis of the third and fourth terminals by a distance equal to the spacing between the terminals of a standard nine volt battery; the first and third terminals are positioned and configured for connection to the terminals of a standard nine volt battery; the second contact is configured to match the battery terminal to which the first terminal is connectable; and the fourth contact is configured to match the battery terminal to which the first terminal is connectable.
 12. A self-contained electrical circuit for insertion in series with a battery power source for battery powered load device including a timer that automatically times out and shuts off the battery power to the load device at a predetermined time after the load device is turned on.
 13. A power control module as in claim 1, wherein: the timer is operative when reset to provide a first output signal during the predetermined timing interval and a second output signal after conclusion of the timing interval; and the control unit is responsive to the first output signal to drive the electronic switch into the conductive state, and responsive to the second output signal to drive the electronic switch into the non-conductive state. whereby the battery is connected to the load device through the first and second terminals only during the timing interval.
 14. A self-contained power control module for an electrically operated load device comprising: a normally open circuit path operable to be closed to couple the module between a power source and a load device; an electronic switch connected in the normally open circuit path, the switch being operable between conductive and non-conductive states by control signals applied thereto to close and open the circuit path; a programmable master controller which is operable to: provide control signals to the electronic switch; provide a timer including reset capability; and a motion detector responsive to motion module to provide a reset signal for the timer, and wherein: the timer is operative when reset to measure a predetermined timing interval; the controller is operative during the timing interval to drive the electronic switch into the conductive state, and otherwise to drive the electronic switch into the non-conductive state, and the controller is further operative to provide a gradual transition between the conductive and non-conductive states of the electronic switch, whereby the current in the circuit path changes gradually when the load device is energized and de-energized.
 15. A power control module as in claim 14, wherein the microprocessor is operable to permit user selection of the timing interval.
 16. A power control module as in claim 14, wherein the microprocessor is operative to permit selectable activation and deactivation of the gradual transition between the conductive and non-conductive states of the electronic switch.
 17. A power control module as in claim 14, wherein the microprocessor is operable to permit selectable activation and de-activation of the timed on-off function and/or the gradual transition between the conductive and non-conductive states of the electronic switch.
 18. A power control module as in claim 14, wherein the motion sensor is positionable remotely from the power control module and is electrically connectable thereto.
 19. A self-contained power control module for an electrically operated load device comprising: a normally open circuit path operable to be closed to couple the module between a power source and a load device; an electronic switch connected in the normally open circuit path, the switch being operable between conductive and non-conductive states by control signals applied thereto to close and open the circuit path; a programmable master controller which is operable to: provide control signals to the electronic switch; and provide a gradual transition between the conductive and non-conductive states of the electronic switch, whereby the current in the circuit path changes gradually when the switch changes from its conductive to its non-conductive state. 